/*
 * @Description: 把网页内容导出为pdf文件
 * @Author: galaxy_yi
 * @Date: 2019-9-18 11:26:32
 * @LastEditors: galaxy_yi
 * @LastEditTime: 2019-09-20 10:05:36
 * @todo:
 */
import html2canvas from 'html2canvas';
import JsPDF from 'jspdf';

/**
 * @param  ele 要生成 pdf 的DOM元素（容器）
 * @param  padfName PDF文件生成后的文件名字
 * */
function downloadPDF(ele, pdfName) {
  let eleW = ele.offsetWidth; // 获得该容器的宽
  let eleH = ele.offsetHeight; // 获得该容器的高
  let eleOffsetTop = ele.offsetTop; // 获得该容器到文档顶部的距离
  let eleOffsetLeft = ele.offsetLeft; // 获得该容器到文档最左的距离
  var canvas = document.createElement('canvas');
  var abs = 0;
  let win_in = document.documentElement.clientWidth || document.body.clientWidth; // 获得当前可视窗口的宽度（不包含滚动条）
  let win_out = window.innerWidth; // 获得当前窗口的宽度（包含滚动条）
  if (win_out > win_in) {
    abs = (win_out - win_in) / 2; // 获得滚动条宽度的一半
  }
  canvas.width = eleW * 2; // 将画布宽&&高放大两倍
  canvas.height = eleH * 2;
  var context = canvas.getContext('2d');
  context.mozImageSmoothingEnabled = false;
  context.webkitImageSmoothingEnabled = false;
  context.msImageSmoothingEnabled = false;
  context.imageSmoothingEnabled = false;
  context.scale(2, 2);
  context.translate(-eleOffsetLeft - abs, -eleOffsetTop);
  // 这里默认横向没有滚动条的情况，因为offset.left(),有无滚动条的时候存在差值，因此
  // translate的时候，要把这个差值去掉
  // html2canvas(element).then( (canvas)=>{ //报错
  // html2canvas(element[0]).then( (canvas)=>{
  html2canvas(ele, {
    dpi: 200,
    // height: ele.scrollHeight,
    // width: ele.scrollWidth,
    // // allowTaint: true,  //允许 canvas 污染， allowTaint参数要去掉，否则是无法通过toDataURL导出canvas数据的
    useCORS: true //允许canvas画布内 可以跨域请求外部链接图片, 允许跨域请求。
  }).then(canvas => {
    var contentWidth = canvas.width;
    var contentHeight = canvas.height;
    //一页pdf显示html页面生成的canvas高度;
    var pageHeight = (contentWidth / 592.28) * 841.89;
    //未生成pdf的html页面高度
    var leftHeight = contentHeight;
    //页面偏移
    var position = 0;
    //a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
    var imgWidth = 595.28;
    var imgHeight = (595.28 / contentWidth) * contentHeight;

    var pageData = canvas.toDataURL('image/jpeg', 1.0);

    var pdf = new JsPDF('', 'pt', 'a4');

    //有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
    //当内容未超过pdf一页显示的范围，无需分页
    if (leftHeight < pageHeight) {
      //在pdf.addImage(pageData, 'JPEG', 左，上，宽度，高度)设置在pdf中显示；
      pdf.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
      // pdf.addImage(pageData, 'JPEG', 20, 40, imgWidth, imgHeight);
    } else {
      // 分页
      while (leftHeight > 0) {
        pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight);
        leftHeight -= pageHeight;
        position -= 841.89;
        //避免添加空白页
        if (leftHeight > 0) {
          pdf.addPage();
        }
      }
    }

    //可动态生成
    pdf.save(pdfName);
  });
}

function downloadPDF1(ele, name) {
  var w = ele.width(); // 获得该容器的宽
  var h = ele.height(); // 获得该容器的高
  var offsetTop = ele.offset().top; // 获得该容器到文档顶部的距离
  var offsetLeft = ele.offset().left; // 获得该容器到文档最左的距离
  var canvas = document.createElement('canvas');
  canvas.width = w * 2; // 将画布宽&&高放大两倍
  canvas.height = h * 2;
  var context = canvas.getContext('2d');
  var scale = 2;
  context.scale(2, 2);
  //  context.translate(-offsetLeft - abs, -offsetTop);

  var opts = {
    scale: scale,
    canvas: canvas,
    width: w,
    height: h,
    useCORS: true,
    background: '#FFF'
  };
  debugger;
  html2canvas(ele, opts).then(function(canvas) {
    allowTaint: false;
    taintTest: false;
    var contentWidth = canvas.width;
    var contentHeight = canvas.height;
    //一页pdf显示html页面生成的canvas高度;
    var pageHeight = (contentWidth / 592.28) * 841.89;
    //未生成pdf的html页面高度
    var leftHeight = contentHeight;
    //页面偏移
    var position = 0;
    //a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
    var imgWidth = 595.28;
    var imgHeight = (592.28 / contentWidth) * contentHeight;

    var pageData = canvas.toDataURL('image/jpeg', 1.0);
    //   var oCanvas = document.getElementById("print");
    // Canvas2Image.saveAsJPEG(oCanvas);
    var pdf = new jsPDF('', 'pt', 'a4');

    //有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
    //当内容未超过pdf一页显示的范围，无需分页
    if (leftHeight < pageHeight) {
      pdf.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
    } else {
      // 分页
      while (leftHeight > 0) {
        pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight);
        leftHeight -= pageHeight;
        position -= 841.89;
        //避免添加空白页
        if (leftHeight > 0) {
          pdf.addPage();
        }
      }
    }
    pdf.save('销售合同.pdf');
  });
}
export default {
  downloadPDF
};
